An optical recording card such as a memory card using an optical recording medium has been usually used for recording and reproduction of information signals with an optical recording/reproducing apparatus having a construction as shown in FIGS. 3A, 3B and 4.
FIG. 3A schematically shows the construction of a recording system of a prior art optical recording/reproducing apparatus. A laser beam emitted from a laser beam source 21 for recording is led through a collimator lens 22 to a rotary polygonal mirror 23. The laser beam reflected by the rotary polygonal mirror 23 is passed through an objective 24 to an optical recording medium 25 of an optical recording card 26. On the optical recording medium 25 of the optical recording card 26, an information signal is optically recorded in each of the pits scanned by the laser beam which is reflected with the rotation of the rotary plygonal mirror 23 at a predetermined timing.
FIG. 3B schematically shows the construction of a reproducing system of the prior art optical recording/reproducing apparatus. A light beam emitted from a light source, i.e., a light-emitting diode 31, for reproduction is passed through a condenser 32 to a half mirror 33. The light beam reflected by the half mirror 33 is incident through a focusing lens 34 on the optical recording medium 25 of the optical recording card 26. The light beam reflected by the recording medium 25 is transmitted through the half mirror 33 to be incident on a line sensor 35 consisting of a CCD (Charge Coupled Device) for reading the information signal. The information signal recorded on the optical recording medium 25 of the optical recording card 26 is read out through conversion of the light beam emitted from the light-emitting diode 31 and reflected by the optical recording medium 25 into an electric signal corresponding to the amount of reflected light beam by the line sensor 35, on which the reflected light beam is incident through the half mirror 33.
With the prior art optical recording/reproducing apparatus, recording and reproducing optical systems are arranged separately as shown in FIG. 4. In this case, the operations of recording and reproducing the information signal are effected at different positions.
With the prior art optical recording/reproducing apparatus where the recording and reproducing systems are provided separately, simultaneous monitoring may not be obtained at the time of the recording operation because the operations of recording and reproducing the information signal are performed at different positions. Further, the light beam for reproducing the information signal is attenuated to one-fourth of the light beam emitted from the light source for reproduction even at the maximum by the half mirror provided in the reproducing system. Therefore, an output having a sufficient signal level may not be obtained from the CCD line sensor. To increase the signal level of the output it is necessary to extend the charge storage time of the CCD line sensor. In this case, a high speed operation may not be obtained.
The present invention has been made in light of the foregoing problems, and its object is to provide a recording/reproducing apparatus for an optical recording card, which has a novel construction, permits increase of the reproduction output level to increase the operation speed and permits simultaneous monitoring at the time of recording of the information signal.